Tourniquet



Oct. 22, 1935. H. CHENERY TOURNIQUET Filed Oct. 30, 1953 Patented Oct. 22, 1935 UNITED STATES PATENT OFFICE 6 Claims.

The invention hereinafter to be described relates, in general terms, to tensioning and looking devices for straps and belts. While applicable for a wide variety of purposes my invention will, in the present instance, be illustrated and described in connection with its use as a tourniquet, a device employed to stay the fiow of blood from a wound in a person's leg'or arm.

Tourniquets are what might be called first aid implements and as such are frequently, in fact more often than not, used by novices. For this reason these devices should be simply made, easy to apply and operate, and capable of fulfilling all demands and requirements of an emergency instrument of this character.

In mounting a tourniquet on an injured member it should be placed near the wound on the side nearer the heart and the constriction of the flesh, brought about by tightening the strap, should be of such strength and intensity as to fully stop the loss of blood through the wound.

In my present invention there are, among others, several features which I will point out as being of essential consequence in its operation, as upon the satisfactory pertormance of a first aid appliance often depends the life of an accident victim.

1. There are no complicated and diflicult-tounderstand manipulations of straps and levers when applying my tourniquet to a wounded arm or leg. The first or primary tension is made with as little difiiculty as donning a body belt or fastening a skate strap. This is of utmost importance, as speed in applying the device will often prevent a person bleeding to death.

2. The secondary or final tightening of the strap is accomplished in as simple a. manner as the first operation and involves swinging a toggle arm, on which one end of the strap is permanently attached, from one end of the bed-frame to its opposite end.

3. By employing a swinging toggle-arm the axis of which advances along the bed-frame as the toggle-arm itself is swung from one end to the other of the bed-frame, actuation of the parts to effect the secondary constriction of the body is made vastly easier than if the two members were pivotally connected and the same amount of secondary take-up or strap movement procured in each instance, the advantage in leverage in the first instance accounting for this.

4. The very convenient facilities for releasing the free end of the belt to procure, in infinite degrees, any desired amount of relaxing of the secondary constriction.

The character of the invention may best be understood by reference to the description found in the following specification when taken in connection with the accompanying drawing disclosing an embodiment which, at the present time, I consider preferable to other possible forms in which the invention might be carried out.

In the drawing- Fig. 1 is a plan view of my tourniquet showing the strap binding an object under primary constrlction;

Fig. 2 is the same, except that the toggle-arm has been swung to the opposite end of the bedframe, giving the strap its secondary constriction movement;

Fig. 3 is a section on line 3-3, Fig. 1;

Fig. 4 is a section on line 4-4, Fig. 2;

Fig. 5 is a section on line 5-5, Fig. 3;

Fig. 6 illustrates the method of releasing the free end of the strap to relax in any amount desired the secondary constriction;

Fig. 7 is a perspective view of the strap-locking element;

Fig. 8 is a plan view of the toggle-arm, and

Fig. 9 is an alternative method of constructing the strap-carrying cross-bar of the togglearm.

Similar reference characters are employed to identify like parts in all views of the drawing.

Referring to the drawing, l is the bed-frame of the tourniquet and 2 the U-shape toggle-arm used in association therewith. The bottom face of the bed-frame is preferably slightly curved so that it may accommodate itself to the rounded contour of the member upon which it is adapted to be mounted.

The bed-frame has two end cross-tie members,

3 and 4, the former serving to prevent the strap being displaced from between the sides of the bed-frame, but more particularly to complete the 40 rectangular structure and provide strength and rigidity therefor. I

The cross-bar 4 besides functioning in the same capacity on its particular end as does the cross-bar 3 on the opposite end of the bed-frame has a further duty to perform which will hereinafter be fully disclosed.

On the top surfaces of the sides of the .bedframe I are gear tooth racks 5, operating, respectively, in which are two gears 6, one on and made integral with each of the branches 2a of the toggle-arm 2; and projecting outwardly from each gear is a gudgeon l. v Secured to each side of the bed-frame l, by

screws 8, is a plate 9 having a longitudinally dis- 55.

posed slot H] in which the gudgeon 1 operates as the gear travels forwardly and backwardly along the rack. On the top of each plate is an inwardly extending shelf 9a, serving as a shield to cover the gear and prevent a persons hands coming into contact therewith.

Interconnecting the sides 2a of the toggle-arm, and passing through the looped end Sa of the strap S, is a strap-carrying bar I I, one end of which is screw threaded into one side of the toggle-arm. This permits of removal of the bar in case the strap needs to be renewed.

It is possible, of course, to make the plate 9 integral with the bed-frame. In this case a slight modification in the construction of the strapcarrying bar is desirable, if not necessary.

In Fig. 8, showing a plan view of the togglearm, there is shown in dot and dash lines the outlines of the two legs on the bottom ends of which the gears 6 are mounted. In the integrally made bed-frame and plate, assembly difiiculties arise in placing the toggle-arm with the gears engaging the racks. It is therefore necessary to spring the legs of the toggle-arm inwardly sufficiently to pass the gears between the overhanging guards 9a (the toggle-arm being held vertically in performing this operation). The legs of the toggle-arm may then be sprung outwardly, seating the gears in the racks; but the act of springing these legs inwardly has developed a set to the metal which cannot easily be taken out. So, preferably, when the parts are designed as Just set forth, I employ a spacer tube l2 which forces the legs outwardly so that the gears are in perfect alignment with the racks. A bolt Ila secures the parts rigidly together, as is shown in Fig. 9.

A finger-hold 2b on the toggle-arm provides means by which to grasp the latter in the swinging operations.

In two oppositely disposed holes l3 in the sides of the bed-frame l is positioned a bar l4, one and preferably having a nick l4a serving as a key to lock the bar in one of the holes l3 and prevent its rotating therein. 7 Revolubly disposed on the bar I4 is a straplocking pawl l5 having serrations l5a on its face. The cross-tie member 4 has a flat, inclined face 4a over which the strap S is drawn in making the primary constriction and on which it is locked against retraction movement by' the pawl IS.

A spring Ida, one end of which is secured to the bar [4 and the other end disposed on the top side of the pawl, acts to maintain a constant yielding pressure of the pawl against the strap 8. A finger-hold l5b' serves as means to disengage the pawl from the strap when it is desired to release the free end of the strap to procure a reduced constriction pressure.

In this connection it might be well to state that in medical practice it has been found that it is dangerous to too greatly prolong the extreme constriction pressure, as, in case this is done, mortification or gangrenous conditions set in, causing serious and sometimes fatal consequences. It is, therefore, necessary to relax the extreme constriction pressure somewhat, and instead of swinging the toggle-arm backward into some intermediate position on the bed-frame to accomplish the above object, I prefer to attain this end by simply relaxing the free end of the belt or strap sufiiciently to permit resumption of circulation in the smaller blood-carrying vessels, which, it may he, were not ruptured in the accident but in which the blood was prevented from circulating when the extreme constriction pressure was applied to the member.

The method pursued in effecting a slackening of constriction pressure in my tourniquet device is graphically disclosed in Fig. 6 of the drawing. 5

While grasping the free end of the strap S between the forefinger and thumb of one hand and holding the strap taut, the pawl 15 is released from engagement with the strap by the other hand. The strap will now recede in the direction 10 of the arrows, reducing the pressure in any amount desired. The release of the strap is in reality a snubbing operation and is under perfect control of the operator who may, if he chooses carry out the releasing operation with one hand. 15

Fig. 6 also illustrates the manner in which the length of the strap which is added to the main binding portion to effect a reduction in constriction pressure is determined.

It will be observed by reference to the draw- :0 ing that the thumb and forefinger grasping the free end of the strap are spaced a distance x from the end of the toggle-arm finger-hold 2b. Now as the strap is released, the thumb and finger, still grasping the strap, will move forwardly 5 with the strap until they abut on the portion 21). At this point the pawl is allowed to again engage the strap, holding the pressure against further reduction. Thus the distance x is the determining factor and establishes a quick and sufil- 30;

ciently accurate gauge in the pressure-reduction operation. It is obvious, too, that the distance 3: may be one-eighth, one-half, three-quarters-in fact any measurement or length of strap which it is desired to add to the body-binding 35 portion thereof. In other words, the pressurereduction process may be accomplished by a strap release almost infinite in its range.

Reverting to a consideration of the method of procuring the secondary constriction of the body a being bound, and with particular reference to Figs. 3 and 4 of the drawing, attention is called to the fact that I do not employ a pivotally mounted swinging element in my tourniquet device. In contrast, my construction involves what might 5 be called a travelling fulcrum obtained by gearteething the ends of the two branches of the toggle-arm and placing the gears in engagement with a, stationary gear-tooth rack over which the gears travel simultaneously with the swinging 50 movement 01' the toggle-arm.

. With this method of tightening the strap still further, after the preliminary binding of the body by the primary constriction has been accomplished, I can quite materially reduce the length of the work arm, that is, the distance from the element H to the element 6; and with the power arm, or the distance from the element 2?) to 6, largely in excess, as to length, of the work arm, a preponderance in leverage favoring the power 60 arm makes for ease in operating the toggle-arm in tightening the strap to obtain extreme constriction.

Now, to obtain the same amount of strap-tightening movement with a lever or crank arm di- 55 rectly pivoted to the bed member would necessitate positioning the bar ll considerably further away from the pivotal point of the lever than is the case with my improved construction. Furthermore, it would require a greater manual ef- 7 fort to swing the lever and would also entail a loss of forward movement of the strap when the lever, which in reality is a crank, approached and passed over the dead center line.

In the present invention the strap is still being tightened even when the toggle-arm is passing over the dead center line, as the geared fulcrum is continuously forcing the toggle-arm forwardly.

In operation, the instrument is laid on the injured member on the side of the bleeding wound nearer the body or torso of the accident victim, usually over the clothing he is wearing. The free end of the strap is passed around the memher and reeved into the tourniquet between the locking pawl and the cross-bar 4 and given a pull of ordinary tensioning eifort, the pawl locking the strap at this time. This gives what I call the primary constriction.

Next, the toggle-arm is grasped by the fingers of either hand and swung over from the position in which it is shown in Fig. 3 to that in which it is depicted in Fig. 4. This brings the tightening efiort to what I designate as the secondary constriction pressure, and this is maintained until the time for relaxing a portion of this last constriction arrives, this operation having been hereinbefore described.

After the toggle-arm has been swung into full constriction position, as seen in Fig. 4, it will, by reference to this figure, be observed that the looped end So. of the strap, seats firmly on the top of the pawl l5, and is maintained in this position due to the fact that the line of draft or pull of the strap from the element H to the element 3 lies in a plane much below the fulcruming point of the toggle-arm.

The present invention embodies all the essential characteristics of a first aid tourniquet, including simplicity, ease in applying and facile in operation- With slight modification in structure it may be used for other purposes.

What I claim is:

1. A tourniquet comprising a bed-frame having two longitudinally extending side portions, a gear-tooth rack on each of the side portions, a bifurcated, swingingly mounted toggle-arm, a gear on the end of each of the bifurcated portions of said toggle-arm, said gears adapted, respectively, to mesh in the two said racks, and means, including a retainer element, to hold the gears in constant mesh with'the racks, whereby in whatsoever angular position said toggle-arm is disposed, its fulcruming contact with the bedframe is such as to prevent slipping longitudinally thereof.

2. A binding device having a constriction strap formed in a single turn around the bound body and the secured ends of which substantially meet when it is under full tension, comprising a bed-frame, a cross-tie member at one end of the bed-frame having a flat, inclined inner face, a pawl adapted to engage said fiat face to lock the strap interposed in any one of various length-wise positions on the strap, a U-shape toggle-arm swingingly mounted on said bedframe, a cross-bar on the toggle-arm on which the opposite end of the strap is looped and secured, means, including two gears and two racks, to progressively advance the fulcrum points of contact of the toggle-arm with the bed-frame while the toggle-arm is being rotated to tension the strap in secondary constriction, a protective guard disposed outwardly of each of said gears, and means to hold said gears against displacement from the racks.

3. A binding device having a strap therefor, comprising an arcuate bed-frame, a U-shape toggle-arm operating in association with and swinging from said bed-frame, means to advance the fulcrum point of said swinging toggle-arm continuously and uninterruptedly along the bedframe, simultaneously with the rotative movement of the toggle-arm, a. longitudinally disposed retaining element on said bed-frame adapted to prevent displacement of the fulcrum 1 5 end of the toggle-arm therefrom, a bar on said toggle-arm on which one end of the strap is nondetachably secured, a locking pawl adapted to secure the free end of the strap to and in various strap-bound positions on the bed-frame, 10 and means on the locking pawl for disengaging it from the strap, whereby any degree or amount of reduction in the constriction pressure of the strap may be procured.

4. A tourniquet having a tensioning strap 15 therefor comprising a bed-frame having two side portions and two end portions, an upstanding plate disposed at each side of the bed-frame and having a longitudinal slot therein, a gear guard extending inwardly from the top of said plate, a 20 gear-rack on the upper side of each of said side portions of the bed-frame, a rotatable, U-shape toggle-arm, a gear on each branch of said togglearm, said gears adapted to operate, respectively in the said racks, beneath the gear guards, a 25 guclgeon extending outwardly from each of the gears into the respective slots in the plates, for the purpose of holding the gears in correct mesh with the racks and prevent displacement of the gears from off the racks, and a cross-bar on said 30 toggle-arm on which one end of the strap is secured, said cross-bar being so disposed that when the toggle-arm is swung forwardly and into the full secondary constriction position, the axis oi. the toggle-arm lies outwardly of the plane in 35 which both the said cross-bar and the rearward end portion of the bed-frame lie.

5. A binding device having a strap for constrioting a body upon which the device is adapted to be mounted, comprising a skeleton form, rec- 40 tangular bed-frame slightly arcuate in side elevation, a cross-bar at each end interconnecting the two side portions of the bed-frame, a geartooth rack on each of the said side portions, a rotatable, U-shape toggle-arm, a gear on the 45 end of each branch of the toggle-arm, said gears meshing, respectively, with the two racks, whereby during the period of rotation of said togglearm it is fulcrumed on the bed-frame at points thereon continually advancing or re-posltioning 50 themselves in the direction of rotation of the toggle-arm, a strap-locking mechanism, including a pawl, operating in association with one of the said cross-bar members of the bed-frame to secure the free end of the strap after being ten- 5 sioned to primary constriction, a spring yieldingly holding said pawl in firm contact with the strap, and a cross-bar on said toggle-arm on which the opposite end of the strap is looped and non-detachably secured, said cross-bar being so 50 disposed on said toggle-arm that, at the termination of the secondary constriction rotary movement of the toggle-arm, the strap loop on said cross-bar will abut on the top of said pawl acting supplementary to said spring in main- 55 taining a strong engagement of the pawl with the strap while it is under extreme constriction.

6. A tourniquet having a binding strap therefor comprising a bed-frame, a toothed rack on each side bar of said bed-frame, a pawl operably 70 mounted on one end of said bed-frame adapted to lock the free end of the strap against retractive movement when said strap is under tension,

a bifurcated, rotatable toggle-arm-disposed on said bed-frame, segmental gears on the inner 7 ends, respectively, of the branches of said togglearm meshing with-and tulcruming on the two said racks, a, strap-carrying bar interconnecting the two branches of said toggle-arm, the opposite end of said strap being attached thereto, and a finger-hold by which the toggle-arm may be swung to either tighten or loosen said strap as it encircles a. body, the fulcrum point of the togglearm advancing in a. continuous movement along the bed-frame during, and in the direction of, the swinging movement 01' the toggle-arm.

HENRY L. CHENERY. 

